I essentially made the sound effects for Tile World in my basement in one weekend (all except one or two sounds, which were rerecorded later on). I originally expected that these would be purely temporary. I was just in the process of adding real sound effects to Tile World, and so I needed a set of wav files that I could legally distribute. Not having an appropriate set of public-domain sounds handy, I set out to cobble together a set to be used for the time being. I fully expected that, like the tile images I drew, someone would eventually volunteer and produce something better to replace them. But, to my surprise, my sound effect actually turned out pretty well, and nobody seemed to think that they really needed replacing. And so they remain in the current version.
As far as equipment goes, all I had was a microphone, my Linux machine, and two programs: sox and snd. I used snd for splicing and chopping parts, and sox provided some simple effects processing. The only other "equipment" was whatever possessions I had that could make noise.
The very first sound I created was force.wav, the sound of the Lynx force floors. For this I used an actual musical instrument -- a pair of orchestral woodblocks. These things are loud enough to fill a concert hall. I recorded a lightly tapped high-low-high-low sequence, and then spliced out the pauses to make it fast and rhythmically perfect.
Once I had that, I sat down and recorded a variety of "mouth sounds", which I then played around with via sox to see what I could come up with. I discovered that using a simple band-pass filter was often enough to transform the sound into something that no longer sounded organic in origin. click.wav, the button sound, was a simple tongue-click altered in this fashion. The sound for picking up an IC chip is named chack.wav because it started out as me saying "chk!". A short, quiet exhalation into the microphone became whisk.wav, which is heard when a fake blue wall is cleared away under Lynx.
I also discovered that the same raw material could be used to provide more than one sound effect. For example, the sound played when picking up an object is ting.wav -- a short, high, silvery chime. This sound is just ding.wav, the sound played when Chip runs out of time on an MS level, played at double speed. The sound comes from an oven timer.
A quick tap on the microphone became bump.wav, played when the Lynx Chip can't make an attempted move. (The analogous sound under MS is oof.wav, which is just me saying "mmf!", unaltered.) This same microphone tap played backwards produced traphit.wav, played when a creature enters a Lynx beartrap. Augmented with some reverb, the sound then became popup.wav, played when Chip walks over a Lynx popup wall.
door.wav is the sound played when a door is unlocked. This was originally a repeated tongue-clucking, which became nicely dry, like metal against wood, after going through a bandpass filter. It may surprise you to know that the same sound was used to make thief.wav. A reverb filter, when the reverb speed is set fast enough, will transform almost any sound into something artificial and electronic-sounding. After putting the original tongue-cluck through the reverb, I spliced together three repetitions, forward-backward-forward, to make the final sound.
If the reverb speed is set too fast, the result will be short, high-pitched, loud, and staticky. This is where I got derezz.wav, the sound played when Chip dies by colliding with another creature in Lynx. I fed ting.wav through the filter to get this sound, but the results were remarkably similar no matter what I started with.
An echo filter can also feed back destructively, but it generally takes longer. Playing ting.wav backwards through such an echo filter gave me teleport.wav, the teleporting sound, which I cut off just before the sound began to distort.
A couple of sound effects are noteworthy for having undergone no processing at all. tick.wav, played during the 15 seconds before time runs out under MS, came from a small metronome. socket.wav, played when Chip opens the chip socket under MS, was made by giving a Chinese abacus a sharp, twisting shake.
Two short musical sounds, death.wav and tada.wav, were also created without processing. Both were made using a melodica, a.k.a a hooter (a simple musical instrument that can basically be thought of as a harmonica with a keyboard).
There are a number of continuous sound effects in the Lynx rules. These required a slightly different approach, so as to make sound effects that can be played in a loop. block.wav was made by rubbing together two cinder blocks. crackle.wav was made by surrounding the microphone with plastic-wrap and gently crumpling it.
skate.wav, heard when Chip is sliding on ice, started out by my saying "shhhhh" into the microphone. I then ran it through echo and reverb filters until the sound had become completely homogenous, and then finally treated it to a high-pass filter. skaturn.wav, played when Chip is passing through an ice corner-wall, was made by running the original skate.wav through a phaser.
slurp.wav, the sound played when Chip is walking past a force floor using boots, is a simple sound made with the tongue. Likewise, snick.wav, meant to sound like cleats on ice, was made with my teeth. plip.wav, heard when Chip is walking across water, was made by quickly tapping my index finger on the surface of water sitting in a pan. All of these sounds were also made without any processing.
bomb.wav, the sound of an exploding bomb, was surprisingly difficult to make. My first attempts were made by subjecting white noise to various filters, but they all sounded wrong. I finally had to make the sound myself. I made an explosion noise, the way kids do when playing at war, and then ran it through a severe low-pass filter until it no longer sounded like a human noise.
The sound that gave me the most trouble was splash.wav, the sound played when a block is pushed into water. I tried recording the sound of an object falling into water, but the result was really a slapping noise. The original MS sound effect is more like water sloshing around, and this was the sort of effect I wanted. After thinking about it all weekend, I finally came up with a way to do it. I took a large glass vase, filled with water, and placed a large pot upside-down on top of it. I then turned the whole thing over, giving me an upside-down water-filled vase inside a pot. I was then able to just lift up the vase, and the water rushing out and filling the pan made the perfect sound effect.